The present invention relates generally to metrology and, in particular, to systems, methods, and computer program products for monitoring the tool health of on a critical dimension scanning electron microscope (CDSEM) and recipe quality on a CDSEM.
Integrated circuits are produced using a semiconductor wafer through a multiplicity of fabrication processes, and associated production tools, including thermal oxidation, diffusion, ion implantation, chemical vapor deposition, physical vapor deposition, epitaxial growth, etch, and photolithography. Advanced process control may rely on monitoring hardware and software at the production tool level to detect and classify faults. Fault detection and classification (FDC) provides the capability to establish a baseline of tool operation and, by comparing the current operation with the baseline, the capability to detect faults as well as classify or determine the root cause of a problem.
During fabrication stages, metrology tools are utilized to monitor the semiconductor wafers and control the production tools for quality and yield improvements. Automated surface inspection provides measurement data that is used to provide process control. A large amount of data is collected during the surface inspection process.
The stability of a CDSEM may be monitored based on repeating measurements made on a daily basis. Due to its infrequency, daily monitoring does not provide an awareness of problems that occur between monitoring runs. Instead, feedback about problems may originate from process modules, not the surface inspection process. In addition, potential measurement recipe issues at the CDSEM may not be detectable by daily monitoring.
Improved systems, methods, and computer program products for monitoring the tool health of a CDSEM and recipe quality on a CDSEM are needed.